Self‐reported sleep duration is not associated with pet amyloid deposition in the oldest‐old: The 90+ Study

Background Some, but not all cross‐sectional studies have suggested a relationship between sleep and PET‐measured amyloid burden in older adults without cognitive impairment. It is hypothesized that amyloid clearance from the brain is related to sleep duration. Our aim is to examine the cross‐sectional association between self‐reported sleep duration and amyloid accumulation in the oldest‐old (90+ years), a group with high prevalence of amyloid burden and sleep changes. Method We analyzed data on 115 participants of The 90+ Study, a longitudinal study of aging and dementia, who reported their monthly average nocturnal sleep duration using the Medical Outcomes Study Sleep Scale (MOS) and had 18F‐florbetapir (amyloid) PET. Sleep duration was categorized as 8 hours. Standardized uptake value ratio (SUVr) was computedfor the posterior cingulate/precuneus (region affected early by Alzheimer’s neuropathological changes) and analyzed both as continuous and binary (SUVr